Disposable absorbent articles typically include a moisture-impervious backing sheet, an absorbent pad, and a liner sheet that contacts the body of a person wearing the article. In addition, elasticized regions are provided around the edges of the article to secure the article about the waist and legs of a wearer. Absorbent articles, such as disposable diapers, typically further comprise opposed front and rear waist portions defining a waist opening, a crotch portion disposed there between, and a pair of elastically contractible leg openings along the side edges of the crotch portion. Disposable diapers having elasticized margins for placement about the legs of a wearer are disclosed in U.S. Pat. No. 4,050,462 and U.S. Pat. No. 5,092,861, and disposable diapers having elasticized side margins and waist band margins are disclosed in U.S. Pat. No. 4,300,562. Further, disposable diapers are conventionally fastened to the body of a user using various attachment means, including adhesive tapes, velcro tapes, spring-like clasps and flaps.
Problems with such diaper designs include shifting, shearing and conflicting movements of the article and the body of a wearer, which distort the article, and thereby cause uneven distribution of the article relative to the wearer's body and/or cause the article to move away from a position in which it is able to reliably and intimately contact the wearer's body. Such distortions cause discomfort and often result in lateral leakage of urinary or fecal material from the diaper. Further, prolonged contact of liquid or semi-solid excreta with the skin of the wearer is also aggravated under such circumstances. For example, the moisture vapor and heat generated by the bodily exudate accumulate in a pocket of the diaper, becoming trapped and then leading to conditions adjacent to a wearer's skin that promote skin irritation, infection, and the like. Although a plastic backsheet, as described above, is generally effective in precluding the passage of bodily exude outwardly, the backsheet is not efficient in preventing lateral leakage of liquids from the opposed side portions of the core sideward between the leg gathers of the backsheet and the wearer's skin. One solution to this problem, the tightening of leg gathers, presents problems in terms of the comfort of the baby and further skin irritation.
Despite previous advancements in the field of absorbent articles, persons of ordinary skill in the art continue their efforts to produce garments that fit better and thus are more comfortable and better able to contain urinary and fecal excretions. Various approaches have been attempted to improve fit and comfort of absorbent articles, while reducing lateral leakage of liquids from such articles, including the use of adhesives in such articles. In particular, direct adhesive attachment of sanitary napkins and body adhering panty shields has been disclosed. However, these approaches are all deficient in terms of effectiveness and/or cost-efficiency, as well as being limited in terms of applicability to specific types of absorbent articles, excluding diapers in particular.
For example, U.S. Pat. No. 6,213,993 B1 discloses an absorbent article having an adhesive on the bodyfacing surface for securement of the article to the wearer. The adhesive has a rheological property tan δ at 20° C. ranging from about 0.01 to about 0.6 at a frequency of about 0.1 to about 1.7 at a frequency of about 1000 radians per second. It is disclosed that, preferably, the adhesive is a hot melt adhesive.
U.S. Pat. No. 6,191,189 B1 discloses a combination of a substrate with topical adhesives for attachment to the skin. In particular the present invention relates to a combination of a substrate with a topical adhesive which can be employed for attachment to the skin in the area where absorption of bodily liquids is desired. The combination provides secure attachment and is pleasing to the skin upon application, yet causes no discomfort upon removal. This is disclosed as being achieved by selecting the chemical composition and rheological characteristics of the topical adhesives and the physical characteristics of the substrate on which the topical adhesive is applied.
U.S. Pat. No. 6,187,989 B1 discloses breathable absorbent articles particularly sanitary napkins, panty liners, adult incontinence products or sweat pads. In particular, the present invention relates to such breathable absorbent articles which are worn by direct attachment to the skin of the wearer in the area where absorption of bodily liquids is desired.
U.S. Pat. No. 6,156,818 discloses disposable absorbent articles, particularly sanitary napkins, pantiliners, adult incontinence products, or baby diapers. In particular the present invention relates to such disposable absorbent articles with side cuffs which are maintained in their in-use position by direct attachment to the skin of the wearer. The topical adhesive attachment of such side cuffs needs to be secured and pleasing upon application and during use of such articles, yet cause no discomfort upon removal of the article. This is achieved by the present invention selecting the rheological characteristics of adhesives for such articles.
U.S. Pat. No. 6,135,988 discloses an absorbent article with an adhesive flap. The absorbent article has a crotch region, a rear waist region, and a body facing surface positionable adjacent a wearer when the article is in use. The absorbent article includes a backsheet, a liquid permeable topsheet attached to the backsheet, an absorbent structure disposal between said topsheet and said backsheet, and a flap positioned in the rear waist region of the article. The flap has first and second oppositely facing major surfaces wherein the first major surface faces the top sheet and the second major surface forms a portion of the body facing surface of the absorbent article. A substantial portion of the front edge of the flap is a free edge and an adhesive is disposed on the body facing major surface of the flap whereby the adhesive may engage the skin of the wearer when the absorbent article is in use. The adhesive flap thereby prevents the formation of a gap between the absorbent article and the wearer's skin near the rear waist region and, thus inhibits the leakage of bodily exudates from the absorbent article.
EP 0 850 628 A1 discloses a tri-dimensional disposable sanitary napkin having a body facing surface and a garment facing surface, a longitudinal symmetry plane, a front end edge and a rear end edge, and comprising a liquid pervious topsheet, a backsheet joined to said topsheet and an absorbent core intermediate the backsheet and the topsheet. The absorbent core has a front portion, a central portion and a rear portion, and comprises a longitudinally oriented ridge in the central and rear portion having a profile that provides for an increased body fit. The sanitary napkin is disclosed as being intended for direct attachment to the skin of the wearer and comprises an adhesive on the body facing surface.
EP 0 850 627 A1, EP 0 850 625 A1, WO 98/27917, WO 98/27918 and WO 98/27916 disclose disposable absorbent articles capable of self shaping in use as sanitary napkins or pantiliners. In particular, the disclosures relate to such disposable absorbent articles which are worn by direct attachment to the skin of the wearer in the area were absorption of bodily liquids is desired and which are activated during use to adapt their shape to the negative three dimensional image of a wearer. The topical adhesive attachment of such articles needs to be secure and pleasing upon application and during use of such articles, yet cause no discomfort upon removal of the article. This is disclosed as being achieved by selecting the Theological characteristics of adhesives for such articles.
EP 0 850 626 A1 discloses disposable absorbent articles particularly sanitary napkins, pantiliners, adult incontinence products or sweat pads. In particular, the disclosure relates to such disposable absorbent articles which are worn by direct attachment to the skin of the wearer in the area were absorption of bodily liquids is desired. The topical adhesive attachment of such articles needs to be secure and pleasing upon application and during use of such articles, yet cause no discomfort upon removal of the article. It is disclosed that in order to provide additional comfort the articles are adaptable, and preferably elastically adaptable.
EP 0 850 624 A1, EP 0 850 622 A1, EP 0 850 619 A1 and WO 98/27910 disclose disposable absorbent articles particularly sanitary napkins, pantiliners, adult incontinence products or sweat pads. In particular, the disclosures relate to such disposable absorbent articles which are worn by direct attachment to the skin of the wearer in the area where absorption of bodily liquids is desired.
EP 0 850 623 A1 discloses disposable absorbent articles particularly sanitary napkins, pantiliners, adult incontinence products or sweat pads. In particular, the disclosure relates to such disposable absorbent articles which are worn by direct attachment to the skin of the wearer in the area were absorption of bodily liquids is desired and which articles are provided with an odor control system.
EP 0 850 621 A1 discloses disposable absorbent articles particularly sanitary napkins, pantiliners, adult incontinence products or sweat pads. In particular, the disclosure relates to such disposable absorbent articles which are worn by direct attachment to the skin of the wearer in the area were absorption of bodily liquids is desired. According to the disclosure, in order to provide the articles with additional comfort they are adaptable, and preferably elastically adaptable.
EP 0 850 620 A1 and WO 98/27915 disclose disposable absorbent articles particularly sanitary napkins, pantiliners, adult incontinence products which have side cuffs or baby diapers. In particular, the disclosures relate to such disposable absorbent articles with side cuffs which are maintained in their in use position by direct attachment to the skin of the wearer.
EP 0 850 618 A1 relates to absorbent articles capable of self shaping in use, particularly sanitary napkins or pantiliners. In particular, the disclosure relates to such disposable absorbent articles which are worn by direct attachment to the skin of the wearer in the area were absorption of bodily liquids is desired and which are activated during use to adapt to their shape to the negative three dimensional image of a wearer.
WO 00/07636 relates to disposable absorbent articles such as diapers and sanitary napkins which are provided with adhesive for attachment of the article to the skin which adhesives provide secure attachment and are pleasing to the skin upon application, yet cause no discomfort upon removal.
WO 98/28024 relates to topical adhesives for attachment to the skin. In particular, the disclosure relates to such topical adhesives which can be employed for attachment to the skin of protective articles, clothing, prosthesis, heat wraps, pads, and/or packs, e.g. for topical relief of pain or simply to provide warming; cold wraps, hearing aids, protective face masks, ornamental articles, or eye wear but excluding absorbent articles. The topical adhesives provides secure attachment and is pleasing to the skin upon application, yet causes no discomfort upon removal. This is achieved by selecting the chemical composition and rheological characteristics of the topical adhesives.
WO 98/28021, WO 98/28016 and WO 98/28014 relate to topical adhesives for attachment to the skin. In particular, the disclosures relate to such topical adhesives which can be employed for attachment to the skin of articles such as protective articles, clothing, prothesis, heat wraps, pads, and/or packs, e.g. for topical relief of pain or simply to provide warmth; cold wraps, hearing aids, protective face masks, ornamental articles or eye wear, but excluding absorbent articles, or also of functional articles such as cosmetic or pharmaceutical delivery articles that provide a substance to the skin, decorative cosmetics or cleaning articles. The topical adhesive provides secure attachment and is pleasing to the particularly the viscous modulus G″ in combination with the thickness C of the topical adhesive layer in which the adhesive is provided for attachment to the skin.
WO 98/23305 relates to a polysiloxane adhesive composition that is disclosed as being useful in attaching products to human skin. It is disclosed that a disposable absorbent product may be prepared that includes the polysiloxane adhesive composition and that may be adhered directly to human skin and peeled off after use with little or no pain to the wearer.
As is apparent from the foregoing, each of the above discussed references presents a variety of means for improving fit and comfort of certain types of absorbent articles, as well as for controlling leakage in certain absorbent garments. However, all of these proposed means are deficient in terms of effectiveness and low product quality, mechanical complexity in design, specificity of application and/or associated cost inefficiencies.
In view of the deficiencies of the various products and processes disclosed in the above discussed references, it is highly desirable to provide cost-efficient absorbent articles that display superior fit, distribution, comfort, leak protection, skin protection, absorbency and/or cost-efficiency. Further, it is highly desirable to provide a cost-efficient process for producing absorbent articles having superior fit, distribution, comfort, leak protection, skin protection, absorbency and/or cost-efficiency, as well as having broad applicability.